Kirk R. Smith, PhD
Professor, University of California, Berkeley
RURAL ENERGY IN CHINA:
Opportunities to Promote Health, Development, and Climate
Shanghai Energy ForumFudan University May 24-27, 2007
Crop wastes33%
Wood21%
Biogas1%
Coal35%
LPG1%
Electricity7%
Kerosene2%
Rural Energy in China: 2004
Ministry of Agriculture
Total
Crop w astes44.3%
Wood36.6%
Biogas1.2%
Coal12.9%
LPG1.2%
Electricity3.7%
Kerosene0.1%
Households
National Bureau of Statistics
70% of total
Household Energy in China
• >65% of China’s population is rural.
• ~ 80% of energy use is simple solid biomass (wood, agricultural wastes)
• ~13% as coal
• Thus, it is still true to say that in China most people rely on biomass fuels for most of their energy
• A situation that has not changed since the mastery of fire by the human race
Rural energysituation is typically complex:
HOUSEHOLD SOLID FUEL COMBUSTION
Why is there so much pollution?What are the major constituents of the
smoke?What adverse health effects have been
measured?What interventions have been evaluated?
Or, since wood is mainly just carbon, hydrogen, and oxygen,doesn’t it just change to CO2 and H2O when it is combined with oxygen (burned)?
Reason: the combustion efficiency is far less than 100%
Woodsmoke is natural – how can it hurt you?
Energy flows in a well-operating traditional wood-fired Chinese cooking stove
In to P o t2 .8 M J
1 8%
In P IC1 .2 M J
8 %
W a s te H e a t1 1 .3 M J
7 4%
W oo d : 1 kg1 5 .3 M J
T ra d itio n a l S to ve
PIC = products of incomplete combustion = CO, HC, C, etc.
15% moisture
Source:Zhang,et al.,2000
A Toxic Waste Factory!!
Typical biomass cookstoves convert 6-30% of the fuel carbon to toxic substances
Toxic Pollutants in Biomass Fuel Smokefrom Simple (poor) Combustion
Small particles, CO, NO2
Hydrocarbons 25+ saturated hydrocarbons such as n-hexane 40+ unsaturated hydrocarbons such as 1,3 butadiene 28+ mono-aromatics such as benzene & styrene 20+ polycyclic aromatics such as benzo()pyrene
Oxygenated organics 20+ aldehydes including formaldehyde & acrolein 25+ alcohols and acids such as methanol 33+ phenols such as catechol & cresol Many quinones such as hydroquinone Semi-quinone-type and other radicals
Chlorinated organics such as methylene chloride and dioxin Source: Naeher et al,J Inhal Tox, 2007
Hazardous Chemicals Identified in Biomass and Coal Smoke
- Carcinogens/mutagens: benzene, 1,3-butidiene, styrene, PAHs, methylated or alkylated PAHs, nitrogen-containing heterocyclic aromatic compounds, etc.
- Irritants: formaldehyde, acrolein, etc.
- Emissions from “poisonous” coal: sulfur (S), nickel (Ni), chromium (Cr), micro fibrous quartz and silica, arsenic (As), fluorine (F), selenium (Se), mercury (Hg), lead (Pb)
Pollution and health effects of indoor coal smoke exposure*
• Lung cancer• Respiratory illnesses• Lung function impairment• Immune system weakening• CO poisoning• Endemic arsenism and fluorosis
*120+ publications from studies conducted in China
Lung Cancer and Indoor Coal Use in China: Review of All Studies (~20)
Unadjusted OR Adjusted*
Men 1.79 (1.18-2.72) 1.51 (0.97-2.46)
Women 1.17 (1.02-1.35) 1.94 (1.09-3.47)
Combined 1.86 (1.48-2.35) 2.55 (1.58-4.10)
*Adjusted for smoking and chronic respiratory disease.
(Smith et al. 2004)
Interpretation:Women who live in households usingcoal have about 2 times more lung cancer compared to thoseliving with other fuels
Children’s Respiratory Illness (Salo et al. 2004, Zheng et al. 2002)
Odds
Ratios
Coal for cooking/ heating
Coal for heating
Coal for cooking w/o vent
Wheezing w/ colds
1.57 (1.07-2.29)
Wheezing w/o cold
1.44 (1.05-1.97)
Asthma 1.5(1.1-1.9)
2.3 (1.5-3.5)
Other illnesses reported include: rhinitis, faucitis, tonsillitis, and pneumonia (Cheng et al. 2002, Zhou et al. 1994).
Lifetime exposure to heating coal smoke and health outcomes children (Qian and Zhang et al, 2004)
0
1
2
3
4
Cough and phlegm Bronchitis Chronic phlegm
Health outcomes
OR
Heavily exposed
Moderately exposed
Lightly exposed
Non-exposed
n = 7,058 school children in four Chinese cities.
Adults’ Respiratory Illnesses (Zhou et al. 1995)
Odds Ratios “Smoky” coal vs. “smokeless” coal
“Smokeless” coal vs. wood
Shortness of breath 1.73
Cough 3.30 1.35
Phlegm 4.23 1.67*Coal and passive smoking together increase prevalence rates of chest illness, cough, phlegm, and shortness of breath in women (Pope and Xu 1993).
CO PoisoningAcute CO poisoning including fatal
casesCO is known neurotoxin Pre-natal and early post-natal
mortality (from mother’s exposure during pregnancy)
Low growth in children (from mother’s exposure during pregnancy)
Endemic Arsenism and Fluorosis(Jin et al. 2003, He et al. 2005, Shraim et al. 200, Finkelman et al. 1999, Yan 1990, Wu and Li 1990, Watanable et al. 1997)
Burning arsenic contaminated coals occurs in Guizhou and Shaanxi Provinces, affecting some 300,000 people.
Use of high-fluorine coals and/or clay binders results in dental and skeletal fluorosis, affecting >10 million people in Guizhou Province and surrounding areas.
Health Effects of Indoor Biomass Combustion*
Use of biomass fuels in households increases risk of
Chronic Obstructive Pulmonary Disease in adult women by a factor of 3.2 (95% CI: 2.3-4.8) .
Pneumonia in children under 5 years old by a factor of 2.0 (95% CI: 1.7-2.5).
*Review of many dozen studies worldwide by World Health Organization (WHO, 2002,2004)
Health Benefits of Fuel/stove Intervention
Best published studies in the world were done by examining introduction of improved coal stoves in China
Improved Stoves Brought to Xuanwei County in early 1980s
• The reduction in particle levels was ~a factor of about three.
• Reduction in lung cancer was ~40% in men and ~45% in women. (Journal of the National Cancer Institute)
• Reduction in COPD rates was also significant at about 50% in both men and women (British Medical Journal)
• Reduction in lung cancer and COPD took 10 years to fully develop after IAQ improvement.
Chinese Burden of Disease from Top 10 Risk FactorsPlus Selected Other Risk Factors
0% 1% 2% 3% 4% 5% 6% 7%
Climate change
Unsafe sex
Physical inactivity
Lead (Pb) pollution
Urban outdoor air pollution
Unsafe water/sanitation
Cholesterol
Low fruit & vegetables
Road traffic accidents*
Overweight
Indoor smoke from solid fuels
Occupational hazards (5 kinds)
Underweight
Tobacco
Blood pressure
Alcohol
Percent of All DALYs in 2000
380,000 Premature deaths per year
Pneumonia in children: 21,000COPD in women: 342,000Lung cancer in women: 18.000
252,000prematuredeaths per year
Percent of all lost life years
ALRI/Pneumonia(meningitis)
Asthma
Low birthweight &stillbirth
Earlyinfantdeath
Chronic obstructivelung disease
Interstitial LD
Cancer (lung, NP, cervical,aero-digestive)
Blindness (cataracts, trachoma)
Tuberculosis
Heart disease
Diseases for which we haveepidemiological studies
CognitiveEffects?
Conclusions: Health
• Household solid fuel combustion leads to high pollutant levels, from both coal and biomass
•Although some improvement has occurred, this pollution still contributes significantly to the national burden of ill health
•hundreds of thousands of premature deaths annually•equal to or greater than that from outdoor air pollution
•Evidence for many adverse health outcomes resulting from smoke exposure is strong worldwide, including lung cancer, respiratory symptoms and diseases, pneumonia, and COPD.
•Although much work has been done in China on lung cancer, there is need for additional work on the range of other diseases to be able to confidentially apply information from other countries
Air pollution measurement studies of Chinese Stove ImprovementsOnly 3 done, all since 2000
• Review of National Improved Stove Program: ~ 400 households in 3 provinces
• World Bank Study: ~460 households in 4 provinces
• Sino-Dutch Study: 140 households in 3 provinces
161
109128 122
86121
101
55
9883
91
86
0
50
100
150
200
250
300
Langzhong YiLong Nanbu Enshi Yongshun All
-39% -34% -43% -40% -51% -41%
Reduction in 24-h PM2.5 (ug/m3)
Amount reduced
~National Standard
Coal stoves
Tests show PIC emissions nearly at LPG levels.
Winner of Chinese national contest announced March 2007 for best stove meeting
emissions and reliability criteria: cost 300Y
A Chinese Biomass Gasifier Stove
Consider the substitution of coal stoves in rural China with advanced biomass gasifier stoves, now commercially available in several provinces
• 300Y retail cost/stove + 50% program cost• 50% of performance in lab • Typical household fuel use• Kyoto greenhouse gases only • Financial calculations as in CDM
requirements• Health calculations based on Chinese data
using WHO methods
Results of Calculations
Cost per saved lost life year: $480 WHO/World Bank recommend that China spend up to
GDP/capita per lost life year saved, $1500 in 2004.
Cost per ton CO2: $5.64 Current price on international exchange 18€
Value of benefits from stove (discounted) $430, 79% from health benefits
Benefit cost ratio based on present value calculations: 8
Health and Greenhouse Gas Benefits of Biomass Stove Options
0
200
400
600
800
1000
1200
1 10 100 1000
Global Waming Per Meal
Coal Stove
BiomassGasifierStove
Co-benefits in China:~$500/life-year saved~$6/t-CO2 averted
Smith et al2000
Rural EnergyDevelopment
Global Climate
MDG HealthGoals
Economic Development
$ per ton-carbon(world carbonmarket)
1-3x $GDP/capita per DALYsaved (WHO/IBRD, etc.recommendation)
How Much to Spend to Support RED?
Local Market
Rural Energy is Linked to Three Major Sectors
Conclusions: Intervention.
• Improved stoves can lower pollution levels substantially, with 40-50% reduction documented
• Reductions in exposures through simple improvements, such as chimney stoves, are intrinsically limited because smoke from the solid fuel is still around the household.
• Future improvements should focus on stoves and fuels that reduce emissions, such as the biomass gasifier stoves being developed in the country.
• Possible to link with international funding for greenhouse gas reductions.
• Substituting cleaner fuels for the poisonous coals used in tens of millions of households should have an especially high priority.
Crop wastes33%
Wood21%
Biogas1%
Coal35%
LPG1%
Electricity7%
Kerosene2%
Rural Energy in China: 2004
Ministry of Agriculture
Total
167 million tons~10% Chinese CO2 emissions
Rural biomass ~15% of all Chineseenergy use
China’s Rural Development
• China now has the largest income inequity in Asia,
• a ratio approaching 20 between the income of the richest 10% and the poorest 10% (UNDP data)
• Japan: 5; India: 7; the Philippines: 16
• This is a direct indication of the rural-urban gap in the country
• Closing this gap is vital to achieving a Harmonious Society in China
Rural Energy as Necessary Condition to Improving Rural Life
• Reliable, efficient, affordable energy needed for rural economic development
• Increasing economic prospects and quality of life in rural areas
• Reducing inequity• Slowing urbanization
• Possible to reduce pressure on fossil fuel resources, both coal and petroleum by use of local renewable resources
• Improve health cost-effectively• Reduce greenhouse-gas emissions cost-effectively
After independence, China had special concerns for rural areas than were
reflected in energy programs for decades
• China led the world in rural energy development in the 1970s and 80s
• It introduced >180 million improved biomass stoves, for example – one of the largest rural development projects in world history
China’s National Improved Stove Program (NISP)
• More than 180 million improved stoves with chimneys were introduced from early 80s to mid 90s
• Evaluation showed that NISP improved energy efficiency and IAQ in rural households, but not sufficiently to meet current Chinese air pollution standards.
• It focused on biomass; the rising coal use in rural areas is threatening to erode the benefits unless action is taken soon. This is particularly a problem in the areas of “poisonous coals”.
Improved Stove in Shanxi
China’s National Improved Stove Program (NISP) 1981-1998
0
50
100
150
200
250
300
1975 1980 1985 1990 1995 2000 2005
Year
Freq
uenc
y (M
ILL
ION
)
improved stoves rural households
Lu Y., 1993
Smith et al.,1993
Qiu et al.,1996
MOE/DOE 1998
CERS and CAREI 2000
China Statistical Yearbook, 2001
Total RuralHouseholds Total Improved
Stoves
Origins of the Chinese Rural Energy Program
At a biogas stove exhibit in Wuhan on April 11, 1958,Mao Zhedong instructed,
“This should be well promoted.”
Today, to help achieve China’ Harmonious Society, a new round of rural energy development is required:
• Electrification• Energy for industry• Improved household fuels• All with
• Advanced technology• Recognition of health benefits• Tapping global resources for climate mitigation• More use of the market
Thank You
This review based on the article being published in the English and Chinese editions of the journal:
Environmental Health Perspectives Vol. 115 #6, June 2007
Zhang J & Smith KR, “Household Air Pollution from Coal and Biomass Fuels in China: Measurements, Health Impacts, and Interventions.”
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